Details It was discovered that SSSD did not properly validate authentication token lengths when processing PAM responder requests. A local attacker could possibly use this issue to cause SSSD to crash, resulting in a denial of service. The problem can be corrected by updating your system to the following package versions: Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.